Home | History | Annotate | Download | only in lib
      1 /*===-- divsc3.c - Implement __divsc3 -------------------------------------===
      2  *
      3  *                     The LLVM Compiler Infrastructure
      4  *
      5  * This file is distributed under the University of Illinois Open Source
      6  * License. See LICENSE.TXT for details.
      7  *
      8  * ===----------------------------------------------------------------------===
      9  *
     10  * This file implements __divsc3 for the compiler_rt library.
     11  *
     12  *===----------------------------------------------------------------------===
     13  */
     14 
     15 #include "int_lib.h"
     16 #include <math.h>
     17 #include <complex.h>
     18 
     19 /* Returns: the quotient of (a + ib) / (c + id) */
     20 
     21 float _Complex
     22 __divsc3(float __a, float __b, float __c, float __d)
     23 {
     24     int __ilogbw = 0;
     25     float __logbw = logbf(fmaxf(fabsf(__c), fabsf(__d)));
     26     if (isfinite(__logbw))
     27     {
     28         __ilogbw = (int)__logbw;
     29         __c = scalbnf(__c, -__ilogbw);
     30         __d = scalbnf(__d, -__ilogbw);
     31     }
     32     float __denom = __c * __c + __d * __d;
     33     float _Complex z;
     34     __real__ z = scalbnf((__a * __c + __b * __d) / __denom, -__ilogbw);
     35     __imag__ z = scalbnf((__b * __c - __a * __d) / __denom, -__ilogbw);
     36     if (isnan(__real__ z) && isnan(__imag__ z))
     37     {
     38         if ((__denom == 0) && (!isnan(__a) || !isnan(__b)))
     39         {
     40             __real__ z = copysignf(INFINITY, __c) * __a;
     41             __imag__ z = copysignf(INFINITY, __c) * __b;
     42         }
     43         else if ((isinf(__a) || isinf(__b)) && isfinite(__c) && isfinite(__d))
     44         {
     45             __a = copysignf(isinf(__a) ? 1 : 0, __a);
     46             __b = copysignf(isinf(__b) ? 1 : 0, __b);
     47             __real__ z = INFINITY * (__a * __c + __b * __d);
     48             __imag__ z = INFINITY * (__b * __c - __a * __d);
     49         }
     50         else if (isinf(__logbw) && __logbw > 0 && isfinite(__a) && isfinite(__b))
     51         {
     52             __c = copysignf(isinf(__c) ? 1 : 0, __c);
     53             __d = copysignf(isinf(__d) ? 1 : 0, __d);
     54             __real__ z = 0 * (__a * __c + __b * __d);
     55             __imag__ z = 0 * (__b * __c - __a * __d);
     56         }
     57     }
     58     return z;
     59 }
     60